420 American Fisheries Society 



quality of the salmon run justifies it, new installations may 

 prove adequate to preserve the fish even under the adverse 

 conditions outlined. The migrating salmon will collect at the 

 foot of the dam and mature there ; they can be stripped and the 

 eggs after fertilization cared for in a hatchery located either 

 above or below the dam wherever conditions for its mainte- 

 nance are most favorable. 



Should conditions below the dam be such that the fish can 

 not be held and ripened, then it is feasible, I believe, though 

 more complex, to solve the problem by lifting them over the 

 dam. I have rough sketches of a carrier I designed for this 

 purpose which has been pronounced practicable and not ex- 

 pensive to operate at such a point. Some experiments are 

 necessary to determine its success in actual operation but I 

 am sure the situation is not hopeless as some incline to believe. 

 Such a carrier is readily adjustable to differences in water 

 level above the dam. 



The handling of the young fish from such a hatchery in- 

 volves some complex questions. They could, of course, be 

 planted easily in the new water body created by the dam, and 

 if distributed rationally, would probably find adequate food 

 and protection, though, of course, a careful study should be 

 made of the new environment beforehand and of the salmon 

 fry after planting. The outlet of such an artificial lake must 

 be fully protected, since either irrigation ditches or the turbine 

 of a hydro-electric plant would destroy the young fish. Such 

 protective measures are not difficult to provide, but must evi- 

 dently be kept in perfect condition during the danger period. 

 Furthermore, provision must be made at the proper time to 

 lift the young fish over the dam and release them in the stream 

 below that they may continue their migration seaward. 



Of course it may be possible to plant the fry in another 

 natural lake where conditions are favorable for their growth 

 and where the outlet stream offers no dangerous obstacles to 

 their natural movement towards salt water when the proper 



